Unit 2 Assignment: Glossary
This is the glossary for Unit 2:
1. alpha decay - process whereby an alpha particle ( 2 protons & 2 neutrons, i.e. the nucleus of a Helium 4 atom) is emitted from a radioactive nucleus, as it changes into the nucleus of a new element.
2. atomic mass number - the total of protons and neutrons in the nucleus
3. atomic number - number of protons in the nucleus
4. atomic weight - from scienceworld.wolfram.com: "the average mass of the naturally occurring isotopes of an element" Actually, the average is weighted by the percentage in which a particular isotope occurs. For example, there's lots more C 12 than there is C 13 and there's even less C 14, so that needs to be taken into account in arriving at the mean.
5. beta decay - in beta decay, electrons are emitted (called beta particles). In the nucleus, a neutron changes into a proton and this causes an electron to be emitted from the nucleus. There's no change in the mass number but add 1 to the atomic number ('cause you've gained a proton)
6. electron - has a negative charge, located around nucleus
7. electromagnetic spectrum: the full range of radiation, arranged by frequency/wavelength
8. energy conservation - energy cannot be created or destroyed but it can be converted from one form to another (ex. light > heat )
9. ether - from scienceworld.wolfram.com: it was hypothesized that there was a medium (dubbed "ether") through which light and other electromagnetic waves traveled
10. gamma decay - Gamma rays are electromagnetic radiation of much higher frequency than visible light, UV and X-rays. Best I can figure, when a nucleus loses energy it emits gamma rays. Gamma radiation can accompany alpha or beta decay. Neither the atomic number nor the mass number are affected.
11. half-life - according to the lecture material for this unit, the half-life for a given radioactive isotope is the time that it takes for half of the radioactive nuclei in a sample to undergo radioactive decay. After 2 half-lives there will be 1/4 the original sample. After 3 half-lives, there will be 1/8. And so on.
12. induced radioactivity - from Quinn: "the temporary radioactivity observed in the vicinity of radioactive elements" (p. 204)
13. nucleus - the mass which is at the center of an atom, this is where the protons and neutrons are
14. neutron - particles in the nucleus that hold no charge, they add to the weight and stability of the nucleus.
15. phosphoresence - from Quinn: "the glow which light excites in certain substances....which continues for a time even after the light source has been removed" (p. 140)
16. pitchblende - the uranium ore the Curies worked with
17. polonium - a radioactive element, discovered by the Curies. It undergoes alpha decay to lead.
18. proton - has a positive charge, located in nucleus
19. radium - in the uranium to lead decay sequence, radium is the result of the alpha decay of thorium. In turn, radium's alpha decay produces radon.
20. radon - a radioactive gas, naturally occurring, that is part of the radioactive decay sequence from uranium to lead. Radon is produced from the alpha decay of radium. It poses a serious health risk.
21. thorium - thorium can be produced by alpha decay from uranium and, as noted above, produces radium by alpha decay
22. transmutation - when one element becomes another because of changes occurring in its nucleus
23. X-ray - electromagnetic radiation of high frequency and very short wavelength. On the electromagnetic spectrum, X-rays are higher frequency than UV rays and lower than gamma rays.
1. alpha decay - process whereby an alpha particle ( 2 protons & 2 neutrons, i.e. the nucleus of a Helium 4 atom) is emitted from a radioactive nucleus, as it changes into the nucleus of a new element.
2. atomic mass number - the total of protons and neutrons in the nucleus
3. atomic number - number of protons in the nucleus
4. atomic weight - from scienceworld.wolfram.com: "the average mass of the naturally occurring isotopes of an element" Actually, the average is weighted by the percentage in which a particular isotope occurs. For example, there's lots more C 12 than there is C 13 and there's even less C 14, so that needs to be taken into account in arriving at the mean.
5. beta decay - in beta decay, electrons are emitted (called beta particles). In the nucleus, a neutron changes into a proton and this causes an electron to be emitted from the nucleus. There's no change in the mass number but add 1 to the atomic number ('cause you've gained a proton)
6. electron - has a negative charge, located around nucleus
7. electromagnetic spectrum: the full range of radiation, arranged by frequency/wavelength
8. energy conservation - energy cannot be created or destroyed but it can be converted from one form to another (ex. light > heat )
9. ether - from scienceworld.wolfram.com: it was hypothesized that there was a medium (dubbed "ether") through which light and other electromagnetic waves traveled
10. gamma decay - Gamma rays are electromagnetic radiation of much higher frequency than visible light, UV and X-rays. Best I can figure, when a nucleus loses energy it emits gamma rays. Gamma radiation can accompany alpha or beta decay. Neither the atomic number nor the mass number are affected.
11. half-life - according to the lecture material for this unit, the half-life for a given radioactive isotope is the time that it takes for half of the radioactive nuclei in a sample to undergo radioactive decay. After 2 half-lives there will be 1/4 the original sample. After 3 half-lives, there will be 1/8. And so on.
12. induced radioactivity - from Quinn: "the temporary radioactivity observed in the vicinity of radioactive elements" (p. 204)
13. nucleus - the mass which is at the center of an atom, this is where the protons and neutrons are
14. neutron - particles in the nucleus that hold no charge, they add to the weight and stability of the nucleus.
15. phosphoresence - from Quinn: "the glow which light excites in certain substances....which continues for a time even after the light source has been removed" (p. 140)
16. pitchblende - the uranium ore the Curies worked with
17. polonium - a radioactive element, discovered by the Curies. It undergoes alpha decay to lead.
18. proton - has a positive charge, located in nucleus
19. radium - in the uranium to lead decay sequence, radium is the result of the alpha decay of thorium. In turn, radium's alpha decay produces radon.
20. radon - a radioactive gas, naturally occurring, that is part of the radioactive decay sequence from uranium to lead. Radon is produced from the alpha decay of radium. It poses a serious health risk.
21. thorium - thorium can be produced by alpha decay from uranium and, as noted above, produces radium by alpha decay
22. transmutation - when one element becomes another because of changes occurring in its nucleus
23. X-ray - electromagnetic radiation of high frequency and very short wavelength. On the electromagnetic spectrum, X-rays are higher frequency than UV rays and lower than gamma rays.
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